2020/09/28 by Tian-Shu Deng, Lei Pan, Yu Chen +1
Mathematics · Physics and Astronomy · #Degenerate energy levels #Dissipation #Electron #Hamiltonian (control theory) #Mathematics #Mechanical and Optical Resonators #Physics #Quantum #Quantum Hall effect #Quantum and electron transport phenomena #Quantum anomalous Hall effect #Quantum mechanics #Quantum spin Hall effect #Symmetry (geometry) #Symmetry protected topological order #T-symmetry #Topological Materials and Phenomena #Topological insulator #Topological order #Topology (electrical circuits) #cond-mat.mes-hall #cond-mat.quant-gas #quant-ph
paper · pdf · doi:10.1103/physrevlett.127.086801
published in Physical Review Letters 127(8), 086801 (American Physical Society) · 5+7 pages, 1+2 figures
arxiv created 2020/09/28 · openalex publication_date 2021/08/17 · arxiv updated 2021/08/25 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
In a closed system, it is well known that the time-reversal symmetry can lead to Kramers degeneracy and protect nontrivial topological states such as the quantum spin Hall insulator. In this Letter, we address the issue of whether these effects are stable against coupling to the environment, provided that both the environment and the coupling to the environment also respect time-reversal symmetry. By employing a non-Hermitian Hamiltonian with the Langevin noise term and utilizing the non-Hermitian linear response theory, we show that the spectral functions for Kramers degenerate states can be split by dissipation, and the backscattering between counterpropagating edge states can be induced by dissipation. The latter leads to the absence of accurate quantization of conductance in the case of the quantum spin Hall effect. As an example, we demonstrate this concretely with the Kane-Mele model. Our study can also include interacting topological phases protected by time-reversal symmetry.